The sheeting unit converts roll/s to sheets. The cutting system is a twin knife (dual rotary) knife configuration. The web passes through the in-feed guide rollers. It is then drawn into the cutting unit by a rubber nip roll with spreader/cross grooves pressing against the driven bottom steel roller. A pair of pneumatic cylinders presses the top nip roll down against the steel cylinder. An air pressure regulator-filter-lubricator unit regulates, cleans and lubricates air supply. The dual rotary drum cutter, the main component of the sheeting unit, is machined from vibration-absorbing, and dynamically-balanced and turns on heavy duty self-aligning spherical roller bearing. HSS quality sheeter blades are installed in the cutting drums that consists of a dual rotating upper and lower knife operating creating a perfect scissor-type cutting action. The angle of the cutting head is fixed to produce precisely perpendicular-cut sheets. The twin knife drum cutter is driven by a computerized servo motor via Siemens PLC through LCD Touch Screen Control Panel for instant change of cut lengths from 450 to 1500 mm.
| Maximum web width |
1900 mm (75") |
| Minimum web width |
450 mm (18") |
| Design speed |
300 meters per minute @ 1-meter cut length |
| Operating speed |
up to 300 mpm |
| Maximum cutting length |
1500 mm (60") |
| Minimum cutting length |
450 mm (18") |
A.The Unwind Stands section
According to user requirements, 1 groups of shaft-less hydraulic unwind stand. Each time 2 rolls of paper can be loaded. The automatic tension controller is equipped to stabilize the feeding tension during the cutting process and ensure cutting accuracy. The paper roll is sent to the unwind stand through the guide rollers, and the hydraulic paper clip can greatly reduce the labor intensity of workers and save the auxiliary time of paper loading. Hydraulic rocker arm can control the left and right direction of the paper roll. The disc type is multi-point pneumatic brake, which has the function of forced braking.(as shown below)
A-1 . Core (users can choose the top type according to the actual situation)
There are currently four types of cores commonly used:
There are four kinds of cores in common use: a. 3-12 inch core; b. 3-6 inch mechanical core; c. 6-12 inch internal expansion core; d. 3-12 inch step core (as shown below)
3-12 inch conical core 3-6 inch expansion core 6-12 inch expansion core 3-12 inch step core
B. Paper feeding, de-curler and tension control
The paper guided out from the unwind stand is leveled by de-curler through feed roll and controlled by tension control system.
B-1 Paper feed roller
Several paper rolls are fed through unwind stand and feed roll to even the paper and press the gap,which makes papers go through cutter section flat.
The paper roller is made of chrome-plated steel that has been tested for balance. The roller surface is smooth and wear-resistant, with good balance and long service life.
B-2 PLC Fully automatic tension control system
Tension control plays an important role in ensuring the cutting accuracy and speed. After leveling, paper feeds into diameter based auto tension control system which can adjust tension automatically by PLC .
Here's how it works:
The tension control system for unwind stand adopts the tension control mode of coil diameter calculation. The speed data of the unwind stand is collected by PLC, and the coil diameter calculation of the unwind stand is completed according to the linear speed of the machine. Users only need to set the brake pressure at the max and mini diameter of the paper roll, tension control system will automatically calculate roll diameter, the brake pressure curve of the slope, according to the multiple sets of paper roll diameter, automatically adjust the brake pressure, to ensure the paper roll in the process of running by large tension constant, variable hours and multiple sets of paper roll calculates independently, to allow multiple sets of paper roll, under different diameter are stable and constant tension can be obtained.
In the control system, unwinding tension is used, each unwind stand is equipped with a photoelectric sensor to check the size of the paper roll diameter in real time. According to the feed roller speed (by install encoder for precise velocity), paper roll speed and feed roller diameter we can get the paper roll diameter change, then according to the change of paper roll diameter we can get tension output value. The linear table is as follows:
Case 1: if set large diameter 1500 mm, tension output 3 KG, small diameter 200 mm, corresponding tension output 0.5 KG (applied to paper grams heavier) then you can get the following the tension of the system output variation and its change trend, as indicated by the arrows, with the smaller diameter of paper roll, , tension becomes smaller, to adapt to the operation of the machine.
C.The Cutting Section
After going through de-curler and tension control, paper is pressed by feed roller at cutting section then goes into cutting section..
C-1.Slitter device (optional)
The pneumatic tool holder is mounted on the holder with dovetail guide rail, which ensures the strong rigidity of the holder. The user can move the pneumatic tool holder to the desired position according to the size of the tool holder, start the air valve of the holder, and conduct the alignment of the upper and lower slitters. Fix upper and lower holders after fine adjustment. The lower slitters connected with belt wheel system and feed roll are driven by the machine. The slitters can trim the paper following the paper feeding direction. In that way, the ideal effect can be achieved
C-3 Rubber roller device to feed paper
The paper guide device is made of pneumatic wear-resisting rubber roller and steel roller. The upper roller can protect the paper surface by using the rubber roller, and it can press the paper tightly and feed the paper stably under the relative pressure. Ensure the balance of paper feeding in the state of emergency stop and start up; reduce repeated paper loading paper and other unnecessary time waste. The lower steel shaft is driven by an independent motor and its control system synchronizes with the cutting tool.
C-4 Cross cutter device
After trimming, two pieces of paper through the feed roller into the crosscutting mechanism for cutting processing. Cutting length and width can be arbitrarily adjusted within the rated range..
C-4-1 Cross cutter
The cutter has two sets of tool shaft synchronous rotation up and down to cut. Driven by servomotor, the upper and lower axes are cut at the same speed. Compared with the single-cutter machine, the finished paper processed in this way has smooth edges, which are not easy to produce rough edges and grooves, has good incision, less dust, higher precision and no need for straight angle adjustment device. The maximum quantity of cutting paper can reach 1000g/m2, and the service life of the blade is longer. Practice has proved that the cutting mode of double rotary knife structure can also ensure the flatness of cutting edge and greatly reduce the production of paper ash and wool when the cutting quantity is high.(as shown below)
D. Convey section
Advanced, stable, reliable paper convey section is an important part of a high-speed paper cutting machine which ensures efficient cutting, paper surface protection, paper edge, smooth stacking, slitting quality and quantity. It is also the key to finished paper processing. Our company adopts the combination of conveyor belt and unfolding conveying and make the paper from the original point contact to facet contact, and transportation more smoothly, efficiently, especially in the end of the transmission part design the structure of pneumatic conveying, and low gram paper, or higher quantitative paperboard, conveying effect can be expected, so as to make the design level of the whole machine has risen to a new height.(as shown below)
E. The Pile Table / Layboy section
E-1 Stack of paper
This layboy has three sides to vibrate at the same time, to ensure the smooth stacking under the automatic paper stacking state. The stack height is controlled by an optical control element, which transmits signals to the variable speed elevator to automatically move the stack platform up and down. Stop the machine until the pile is up to rated height. (see figure below)
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